cdnguy

So for us that run over the 200lbs mark what tire pressure should we go with. Each tube usually has a range on it, should we run on the lower or higher end of that range or does it matter? I feel that if I run too low pressure the tire appears flat and rolls less efficiently and too high and I fear my arse will be the straw that broke the camels back, so to speak. Just curious what others do.

rgconner

I run the high end, keeps the pinch flats away.

Think of it this way: do you put more or less air in your car tires when hauling a heavy load?

mkadam68

There are three pressure ranges you need to keep in mind: tube (although I don't recall seeing tube manufacturers put this on their product), tire, and rim. Run the lowest maximum of those.

pdlamb

Depends on the tire. With a 700Cx32, I usually run about 80 +/ 5 psi. That's below the rating on the side of the tire. If you're running 23 or 25, expect to need a bit more.

There's a chart somewhere on the web that shows inflation by tire size and load for an "ideal" 15% drop, but I can't find it with a quick search right now.

bobwysiwyg

https://www.google.com/search?q=bike...mOXwTSTVpdCpM:

sdmc530

Doesn't even hit 200lbs. Or I can't see it. I use the highest allowed on the tire. Ride might be a tough rougher but I don't get flats very often either.

nfmisso

Use linear interpolation to get to higher loads.

On my commuters I have:
(930) front: 32-559 Nashbar City Slick rear: 40-559 Kenda Kwest; Velocity Aeroheat rims, Wheelmaster 40H tandem hubs, Wheelsmith spokes, I run 100 psi (90 to 105 psi) front and rear.
(720) front: 28-622 Kenda Kwest rear: 35-622 Kenda Kwest; Velocity Dyad rims, Wheelmaster 40H tandem hubs, Wheelsmith spokes, I run 95 psi (85 to 100 psi) front and rear.

I have about about 15 lbs in my panniers, plus: bike, fenders, rack, lights, etc and weigh over 350lbs; total all weight is over 400 lbs.

I use Sunlite TR tubes.

Never had a pinch flat. Have had glass shard, nails, etc, but very rare.

cdnguy

Lol I have no idea! I guess if I knew that I wouldn't have needed to ask the question.

Moriarty

I usually run towards the high end. For my road bikes, that means around 105-110psi on 23 or 25mm tires. For my hybrid, it's 80psi on 32mm tires. For my beat up old mountain bike, it's 60psi on what ever big tires it has.

catgita

15% sag is usually a good rule. The thing us clides need to watch out for is that the tire may not be wide enough to support our weight. Looking up my weight on the chart for a 25mm tire, that puts me well over the maximum rated pressure. But with a 38mm tire, I only need 50psi, which is well under the rated pressure for the tires I use. And way fewer flats at these pressures as well.

rgconner

It is in your owners manual, =)

This is an example from an Audi A6 :



I bet very few people bother to notice their vehicle comes with such suggestions. I guess I knew because I grew up around auto/motorcycle mechanics.

chaosdsm

This chart should work for riders + Bike weight of up to about 320 pounds. Chart is based on load per wheel, so for me on a short ride, at 210lbs + 26lbs bike weight + 14lbs water, snacks & extras = 250lbs - typical weight distribution is supposedly 45% front / 55% rear which equals 112.5lbs of load on the front wheel & 137.5lbs of load on the rear wheel. I have 700x25C tires. Using that chart, it appears that my front tire should be about 100psi (which it is) & rear should be about 125psi, but it's also at 100psi.

sdmc530

sorry about that..my bad

Podagrower

Tire pressure and weight carrying capacity are linear (like nfmiso said). The same tire can carry twice the load at 100 psi that it can at 50 psi. Some people believe the only PSI you should use on a bike tire is the maximum, others follow the Berto tire drop pressures (that 15% drop that catgita mentioned). Personally I use Berto (there's an app for that) but it frequently means my rear tire is at max PSI anyway.

cdnguy

That was also lost on me, but now that chart is so much more useful!

Sean

donalson

I like to use this calculator... I use the 2nd one with the 40/60 as I sit more upright... i'm too lazy to do the proper 15% sag number calculatons...

Bicycle tire pressure calculator

I also use 32c tires because of the pressure required for a 330# rider... (44c tires on my touring bike)... I end up running a bit higher than the max tire pressure... it's within the max range on the rims though...

rumrunn6

max rear, been playing with the front. have yet to try a lower pressure on my front road bike tire but looking forward to it cuz I hope it will be less twitchy. meaning easier to keep straight & maybe ride w no hands easier. sometimes that's useful when I want to mess w a glove or camera. last ride out (off road) was very happy with a lower front pressure

Jarrett2

I've been playing with it a lot lately. I used to run 120 front and back and that was with 19mm wide rims and 25mm tires.

I've since gone to 23mm wide rims and 28mm tires (both of which allow for less pressure) and have dropped the tire pressure significantly.

The ride just gets better and better. I think the last time I went out, I was at 80 front and 95 rear. Maybe 290 lbs when you factor in bike, all the stuff and me.